Burns will cover Harlequins' Jordan Turner-Hall's injury while Twelvetrees is added with England monitoring London Irish centre Jonathan Joseph's fitness. Neither Turner-Hall nor Joseph played for their respective club sides at the weekend.

Joseph's ankle injury hails from London Irish's round seven loss to Harlequins while Turner-Hall, who is struggling with an inflamed knee, was released to Harlequins ahead of their match with Gloucester on Saturday but did not feature in their matchday squad.

In contrast, both Twelvetrees and Burns turned out for Gloucester in the match at the Stoop. And both played well with Twelvetrees grabbing a try while Burns knocked over 20 points with the boot. Neither Burns nor Twelvetrees have played for England and could make their debut for the national side if they get the nod for their match with Fiji on Saturday.

The clash will be the first of four Tests for England over consecutive weekends and the side are already having to contend with an injury list that includes Northampton Saints duo Dylan Hartley and Courtney Lawes.

"Freddie has been playing well in the Aviva Premiership and, with Jordan needing to stay at Harlequins for treatment, we are keen to have a look at him. JJ is continuing his recovery from an ankle injury and this is a good chance to get Billy in for training," England coach Stuart Lancaster explained. "As last week, George Robson and David Paice come in as an injury replacements for Courtney Lawes and Dylan Hartley.

"Both will be assessed and treated in camp and it is important that they stay with the squad as much as possible. We had a productive week at St George's Park and got a lot of work done. Now we are back at Pennyhill we will sharpen our focus towards Fiji on Saturday."